Results 81 to 90 of about 21,917,261 (298)

Seeds of change: The impact of Ethiopia's direct seed marketing approach on smallholders' seed purchases and productivity

American Journal of Agricultural Economics, EarlyView.
Abstract While multiple factors explain low adoption rates of improved varieties by small‐scale farmers in sub‐Saharan Africa, a key supply‐side constraint is the limited availability of seed embodying new traits in the volume, quality, price, and timeliness required by farmers. This constraint is partly attributable to classical failures in the market
Dawit Mekonnen, Gashaw T. Abate, Seid Yimam, Rui Benfica, David J. Spielman, Frank Place   +5 more
wiley   +1 more source

Structure and Function of a Multi‐Megadalton Virus‐Like Proteolytic Dodecahedron

Angewandte Chemie, EarlyView.
Zuzalysin, a virulence metallopeptidase of the periodontal pathogen Porphyromonas gingivalis, is secreted as a latent, flexible ≈95‐kDa monomer. Calcium triggers cysteine‐switch activation and hierarchical assembly into pentamers, bipentamers, tripentamers, and a ≈5.6‐MDa, ≈355‐Å dodecahedron. Structures at 1.8–3.6 Å reveal a virus‐sized catalytic cage
Mariusz Madej, Arturo Rodríguez‐Banqueri, Danuta Mizgalska, Borys Szmigielski, Zuzanna Nowakowska, Małgorzata Benedyk‐Machaczka, Monika Bzowska, Katarzyna Mikruta, Juan Sebastián Ramírez‐Larrota, Chinanu Agunanne, Olivier Julien, Anthony J. O'Donoghue, Carsten Scavenius, Mario López‐Martín, Enrique Marcos, Łukasz Koziej, Sebastian Glatt, Pablo Guerra, Ulrich Eckhard, Jan Potempa, F. Xavier Gomis‐Rüth   +20 more
wiley   +2 more sources

Using palynological evidence from royal jelly to mediate the spread of Paenibacillus larvae in Brazil

Hoehnea
Royal jelly may contain pollen grains and their presence can be used to determine the phytogeographical origin of the product. This study analyzed the phytogeographical origin of commercial royal jelly samples from São Paulo State, tested as part of the ...
Cynthia Fernandes Pinto da Luz, Lubiane Guimarães-Cestaro, José Eduardo Serrão, Dejair Message, Marta Fonseca Martins, Maria Luisa Teles Marques Florêncio Alves, María Carmen Seijo-Coello, Érica Weinstein Teixeira   +7 more
doaj   +1 more source

Iron Age peat cutting and ritual depositions in bogs – new evidence from Fuglsøgaard Mose, Denmark

Danish Journal of Archaeology, 2020
With the discovery of peat and gyttja deposits containing archaeological remains, sealed below colluvium, at Fuglsøgaard in eastern Jutland came a rare opportunity to investigate an Iron Age votive bog with abundant traces of peat cutting and subsequent
Morten Fischer Mortensen, Charlie Christensen, Karin Johannesen, Ernst Stidsing, Reno Fiedel, Jesper Olsen   +5 more
doaj   +1 more source

Climate change and perennial crop production: Evidence of yield impact and adaptation in California

American Journal of Agricultural Economics, EarlyView.
Abstract Perennial crops are economically important. They contribute to food security, providing essential nutrients that are often lacking in annual crops, and provide additional environmental benefits compared with annual crops. Despite their importance, empirical research on the impacts of climate change and adaptation on perennial crops remains ...
Yuanyuan Wen, Wei Zhang, Julian M. Alston   +2 more
wiley   +1 more source

Income sharing for common pool resources with uncertain productivity

American Journal of Agricultural Economics, EarlyView.
Abstract We address the interconnected issues of externalities in the use of a natural common‐pool resource system and adverse effects of environmental uncertainty on risk‐averse resource users. We set up a simple analytical model and derive conditions such that insurance by means of an income sharing mechanism mitigates externalities and hence ...
Claudia Kelsall, Martin Quaas, Nicolas Quérou   +2 more
wiley   +1 more source

Bees Diversity on Flowers of Eremanthus spp. (Asteraceae)

Floresta e Ambiente
Bees are considered important pollinators due to their fidelity to plants, enabling the maintenance of gene flow between plant species. The objective of this study was to recognize the visit of bees in two Candeia species, Eremanthus erythropappus and ...
Ana Paula de Souza Medeiros Santos, Sebastião Lourenço Assis Júnior, Anete Pedro Lourenço, Evandro Luiz Mendonça Machado   +3 more
doaj   +1 more source

Interactions between maternal provisioning and natural selection on seed mass fluctuate across heat waves

American Journal of Botany, EarlyView.
Abstract Premise Changing climates are leading to more frequent and severe heat waves, potentially threatening plant populations. Both acclimation to stress and selection for heat‐escape or heat‐resistance phenotypes occur during heat waves. However, plastic responses and selection do not necessarily interact cohesively—even producing trait responses ...
Lana F. Gaspard, Elissa Harb, Stacy D. Holt Jr., Courtney M. Patterson, Nicholas J. Kooyers   +4 more
wiley   +1 more source

Short-Term Climatic Oscillations in the Central Region of the East-European Plain at the Beginning of the Holocene Based on Palynological Studies of Lacustrine Deposits

Quaternary
The Preboreal (11.75–10.70 ka BP) is still the least paleogeographically studied time interval in the central part of the East European Plain. High-resolution multi-proxy studies of lacustrine sediments at the Seltso site located in the Desna River ...
Olga Borisova, Natalia Naryshkina, Andrey Panin   +2 more
doaj   +1 more source

Reproductive stages in lowbush blueberry (Vaccinium angustifolium) occur earlier with increasing temperature

American Journal of Botany, EarlyView.
Abstract Premise Climate change is altering the timing of many plant phenological events, yet most studies focus on flowering, with less attention given to later reproductive stages such as fruit development and ripening. Vaccinium angustifolium (lowbush blueberry) is an important perennial berry species that may be sensitive to these changes.
Jenna Floyd, Elise Cadiou, Alain G. Belliveau, Zoe A. Panchen, Terrell T. Roulston, Zoë Migicovsky   +5 more
wiley   +1 more source